The invention relates to a holding arm system, in particular for holding medical instruments in the region of an operation.
Such a holding arm system is known from DE-A-2700661. For a holding arm system which is suitable for holding surgical instruments in the region of an operation, the following requirements are present:
The holding arm system must have a locking, which can be operated from one point. With this locking, all those arm joints necessary for the change in position of the surgical instrument mounted at the distal end of the holding arm system must be easily fixable and releasable again. PA1 Each point in the operating region must be able to be reached with the instrument e.g. an endoscope, which depends on the respective operation technique. Further, the holding arm system must have a sufficient number of arm segments connected to one another in a jointed manner such that the instrument is movable over the operating table over a large as possible spacial angle and over a sufficiently large distance from the fastening point of the holding arm system. PA1 The higher the number of arms connected to one another in a jointed manner, the more important becomes the requirement that the locking is reliable and easily releasable for all arm segments. PA1 an axially mounted shaft in each arm tube shank, said shaft in each case engaging, with engaging means on the end face side within the hinge joints, on the neighbouring shank, and PA1 on one of the arm segments, a single fastening handle which on operation mechanically engages into braking means and brings said braking means in frictional engagement with a braking surface fixed to an arm tube in such a manner that in cooperation with the connected shafts, the whole holding arm system is locked. PA1 Since the joints of the holding arm system are formed as hinge joints, each joint in the locked condition may be locked with a high locking force by way of the shaft guided in the inside of the holding arm tube. PA1 Because the holding arm segments are formed tubular, the inside can be sealed against fluid and vapour and a sterile covering hose may be pulled from the end effector interface via the holding arm system up to the holding block. PA1 Since the fastening device comprises a handle formed on a single arm segment, with a simple hand grip, the whole holding arm system may be locked and released again. PA1 a holding arm sectioned into arm segments and joints connecting these arm segments, PA1 a holding block mounted to the proximal end of the holding arm for fastening the holding arm onto a stationary object, wherein the arm segments comprise, PA1 the joints in each case are formed as hinge joints each provided with a pivoting region, and wherein PA1 a fastening device can be operated from a single arm segment for locking the holding arm and which by way of a braking device locks a given shaft with respect to the assigned arm tube, so that due to the positive fit connection of the shafts the whole holding arm is locked.
The holding device for surgical auxiliary instruments described in the previously mentioned DE-A-2700661, for the locking of these instruments, comprises between an end effector interface and a holding block, a two-armed joint stand having a middle pivot joint. This joint stand with its one side is coupled to the end effector interface via a ball joint and on the other side is coupled via a further ball joint to an extension arm, which, relative to the holding block, can be tightened thereto at any position of height or rotation. The joint stand is formed tubular, and in the inside of this tube there is mounted an axially moving push rod which is pretensioned in the direction of a chuck lever by way of a spring. For its part, the chuck lever, for locking the connecting arm segment, operates conical sliding members which, when they are displaced by the chuck lever, displace the push rod in the direction of the connecting joint, so that a braking member attached here to the push rod effects the locking of this joint. This document also discloses a sterile hood which on application covers the whole holding arm system with the exception of the end effector interface and the applied instrument.
From EP-A-0293760 there is disclosed another holding arm system which is composed of several relatively freely moving arm segements in a first operational mode. The joints which connect these arm segments may be impinged upon by a small resistance force in a second mode of operation, so that a user can set the position of an instrument mounted at the distal end of the instrument to the desired setting whilst overcoming a small holding force, and it then remains at this setting.
In order to impinge the joints with this holding force, pressure tubes or hoses are guided through the arm segments and which undergo a pressure or vacuum by way of a pump. This means that this holding arm system is not securely lockable.
In view of the above state of the art it is the object of the invention to provide a holding arm system which can securely and rigidly hold a preadjusted instrument in its position without the effect of force, so that this locked position may only be deliberately changed by operating personnel.
This locking should be able to be operated from a single point, so that all arm joints of the holding arm system, necessary for the positional change at the distal end, may be easily lockable and releasable. The holding arm system must also be so designed that every point in the operation region can be reached by an instrument mounted on the distal end of the holding arm system.
Furthermore the system must guarantee that a suitable end effector interface formed as a quick change unit fulfils all the hygenic requirements of the respective operational technology. One requirement corresponds essentially to a separation into a sterile and semi-sterile section of the holding arm system.